package com.example.reggie.controller;

import com.example.reggie.common.R;
import lombok.extern.java.Log;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.UUID;

/**
 * 文件上传下载
 */
@Slf4j
@RestController
@RequestMapping("/common")
public class CommonController {

    @Value("${reggie.path}")
    private String basePath;

    @PostMapping("/upload")
    public R<String> upload(MultipartFile file){
//        log.info(file.toString());
        //file是一个临时文件，需要转存到指定位置，否则本次请求后临时文件会删除

        String originalFilename = file.getOriginalFilename();   //abc.jpg
        String substring = originalFilename.substring(originalFilename.lastIndexOf("."));   // .jpg

        //使用uuid重新生成文件名，避免文件名重复造成文件覆盖
        String filename = UUID.randomUUID().toString() + substring;
        //创建一个目录
        File dir = new File(basePath);
        if (!dir.exists()){
            //如果目录不存在，则创建
            dir.mkdir();
        }
        try {
            //将文件转存到指定位置
            file.transferTo(new File(basePath + filename));
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
        return R.success(filename);
    }

    /**
     * 文件下载
     * @param name
     * @param response
     */
    @GetMapping("/download")
    public void download(String name, HttpServletResponse response){

        try {
            //输入流，通过输入流读取文件内容
            FileInputStream fileInputStream = new FileInputStream(new File(basePath + name));
            //输出流，通过输出流将文件写回浏览器，在浏览器展示图片
            ServletOutputStream outputStream = response.getOutputStream();

//            response.setContentType("image/jpeg");

            int len = 0;
            byte[] bytes = new byte[1024];
            while ((len = fileInputStream.read(bytes)) != -1){
                outputStream.write(bytes, 0, len);
                outputStream.flush();
            }

            //关闭资源
            outputStream.close();
            fileInputStream.close();
        } catch (Exception e) {
            e.printStackTrace();
        }


    }

}
